1. Field of the Invention
The present invention relates to a writing tool and more particularly to an applicator for the correction of clerical errors or to a writing tool such as a ball-point pen wherein a tip containing a rotary element, the rotary element being biased forward into contact with an inward front-end edge of the tip by means of a coil spring, is connected with an ink tank through a ferrule holder. The ink tank containing a solid-liquid separable ink and an agitation member, and when the applicator or the writing tool is to be used, the rotary element retracts from the inward front-end against the coil spring, allowing the ink to be discharged and transferred onto a writing paper.
2. Description of Background Information
According to a conventional writing tool of this type, as shown in FIGS. 8A and 8B, a tip 21 containing a rotary element 22 inside its front end, the rotary element 22 being biased forward into contact with an inward front-end edge 21-1 of the tip by means of a coiled spring 20, is connected with the front end of an ink tank 24 through a ferrule holder 23. The rotary element 22 retracts away from the inward front-end edge 21-1 of the tip 21 against the coiled spring 20, whereby a solid-liquid separable ink 25 which has been fed from the ink tank 24 into the tip 21 through the ferrule holder 23 is discharged and transferred onto a writing paper or the like through a front-end opening of the tip formed by the retreat of the rotary element (this construction is known, for example, in Japanese Utility Model Laid-Open Nos. HEI 5-51480, 5-58362, 5-76568, 6-7984 and 6-7985).
The solid-liquid separable ink has the property that when left standing for a long time, the solid component of the ink is precipitated and agglomerated to form a cake. Therefore, when the writing tool is to be left standing for a long time after use, it is necessary that the ink residue in both ferrule holder and tip should return quickly into the ink tank. Otherwise, the solid component of the ink would begin to precipitate, with agglomeration of the precipitated solid component and formation of a cake. This may result in that the motion of the coiled spring and that of the rotary element are prevented completely by the cake. In other words, the opening/closing function of a valve mechanism constituted by both the inward front-end edge of the tip and the rotary element is lost completely by the cake, with the result that the writing tool eventually becomes unemployable and is compelled to be discarded.
In the above conventional writing tool, however, the sectional area of the ink flow path from the ferrule holder 23 to the tip 21 is narrow and the ink 25 resists flow, so even if the writing tool after use is left standing with its pen point facing up, the ink 25 remaining in both tip 21 and ferrule holder 23 is unable to return completely into the ink tank 24. Consequently, with the lapse of time, the ink 25 separates into solids and liquid and the solid component begins to precipitate, with agglomeration and formation of a cake within the tip 21 and the ferrule holder 23. Thus, in the conventional writing tool containing a solid-liquid separable ink in the ink tank, the cake formed by such precipitation and agglomeration of the solid component of the ink frequently gives rise to problems, and a remedial measure has been desired.
Accordingly, it is an object of the present invention to provide a writing tool wherein the residue of ink in both the tip and ferrule holder returns quickly into an ink tank by turning the pen point upward after use. It is another object of the present invention to provide a writing tool wherein a coiled spring for biasing a rotary element forward can be mounted easily so as to exert a constant biasing force continually on the rotary element.